In 2005 during excavation works in Gniezno on Mount Lech a half of a leaden ducal seal (bull) was found within the early medieval hillfort. The seal lay in the layer dated by means of ceramics to approx. the first half of the twelfth century. It is the third leaden seal found recently in Poland after the fragment of the bull from Glebokie near Ostrów Lednicki, Wielkopolskie Voivodeship, and the wholly preserved bull from Ostrów Tumski in Poznan. The fourth bull. Analogous to the Gniezno specimen, was found in 2006 near Sierpc in the vicinity of Plock in Mazovia. The obverse of the Gniezno bull (a duke standing facing, holding a spear in his right hand) has been struck with the same seal-die as the obverse of the Mazovia bull. Their reverses (the bishop standing facing), however, despite general similarity, are different. The Gniezno bull shows certain resemblance with the one from Glebokie near Ostrów Lednicki. The bulls from Gniezno and Mazovia belonged to a twelfth century Polish duke named Boleslaw or Wladyslaw. The bishop upon reverse is no less a person than St Adalbert.